Alligator-shears.



A. 0. SLENTZ.

ALLIGATOR -SHFARS. APPLICATION FILED APR. 12, 1912.

Patented Dc. 29, 1914 5 SHBETSSHBET 1.

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A. 0. SLBNTZ.

ALLIGATOR SHEARS.

APPLICATION FILED APR. 12, 1912.

1 1 22, 3 1 9 Patented Dec. 29, 1914.

5 SHBETSSHEBT 2.

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ALLIGATOR SHEARS.

APPLICATION FILED APR. 12. 1912.

1 1 22,3 1 9. Patented Dec. 29, 1914.

5 SHEETS-SHEET 3.

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ALLIGATOR SHEARS.

APPLICATION FILED APR.12, 1912.

Patented Dec. 29, 1914.

12, 1912- v 29 SHEET 5- A Ru w mm 6H m km W mm ALBEETUS O. SLENTZ, OFCANTON, OHIO, ASSIGNOR TO THE CANTON FOUNDRY AND MACHINE COMPANY, OFCANTON, OHIO, A CORPORATION OF OHIO.

ALLIGATOR-SHEARS.

Application filed April 12,1912. Serial No. 690 289.

To all whom it may concern Be it known that I, ALBERTUS O. SLENTZV, acitizen of the United States, residing at Canton, in the county of Starkand State of Ohio, have invented certain new and useful Improvements inAlligator-Shears, of which the following is a specification.

The invention relates to power shears for cutting metal bars and plates,and more particularly to that type of cutting machines colloquiallycalled alligator shears; and the general object of the invention is toprovide means for automatically stopping the shears in open positionafter a cut has been made.

In ponderous machines of this type, the heavy weight of the rear end ofthe shearing arm, with the added weight of the pitman and the cranks,has rendered it difficult to stop the machine in open position, becausethe momentum of the downward movement of these parts in opening theshears tends to cause the cranks to swing beyond the pendent positionand thence upward again beyond the range of the clutch disengagingmechanism. thus resulting in a continuous operation of the shears. Thisdifiiculty is overcome, and ancillary advantages are attained, byproviding means for equally balancing the excessive weight of the rearend of the shearing arm, the pitmen and the cranks, thus relieving thecrank shaft from the weight of these parts; and by providing a frictionspring for stopping the cranks in the proper position when the clutch isreleased and the shears open.

A preferred embodiment of the invention, thus set forth in generalterms, is illustrated in the accompanying drawings, forming part hereof,in which- Figure 1 is a side elevation of the improved shearing machine;Fig. 2, a plan view thereof; Fig. 3, a longitudinal section thereof online 33, Fig. 2, showing the balancing spring-case in median linesection; Fig. 4, a cross section thereof on line 44, Fig. 2; Fig. '5, afragmentary outer end view of one gear wheel hub, showing the clutchfinger in releasing position; Fig. 6, an inner end view of one clutchhead; Fig. 7, a fragmentary section showing the gear wheel hub on line77, Fig. ,5,'and the clutch head on line 77, Fig. 6'; Fig. 8, a

Specification of Letters Patent.

detached perspective View of the clutch block; Fig. 9, a fragmentaryperspective view of the end of the clutch finger; Fig. 10, a fragmentaryperspective view of the end of one crank; and Fig. 11, a detachedperspective view of the friction spring.

Similar numerals refer to similar parts throughout the drawings. y I

On the side members 1 of the base or frame of the shearing machine areformed or secured the journal bearings 2 for the driving shaft 3; thejournal bearings 4 for the crank shaft 5 and the journal bearings 6 forthe pivot shaft 7 of the shearing arm 8. The driving pulley 9 is securedon one end of the driving shaft and the balance wheel 10 on the otherend thereof, and the two cog pinions 11. are" secured on the same shaft,preferably inside the journal bearings 2; and the cog gears 12 arerotatably mounted on the crank shaft 5 preferably outside the journalbearings 4; and it is Patented Dec. 29, 1911..

evident that, when power is applied as by pin 14; on which wrist pin isjournaled the I lower end of the pitman 15, the upper end of whichpitman is journaled on the pivot pin 16 extending between the sideflanges 17 of the bifurcated rear end of the shearing arm 8; and it isevident that a rotation of the crank shaft 5 will cause an oscillationof the shearing arm 8 onits pivot shaft 7 for an operation of theshearing machine in the usual manner. 1

For the purpose of the present invention, the balancing springs 18 areprovided and, as shown, four coil springs are arranged in theextensiblecase 19, the lower member of which is provided with thecentral rounded boss 20 which is seated inthe corresponding socket 21provided in the base bar 22; and the upperinember of which case isprovided withthe central rounded boss 20 which is seated in thecorresponding socket 23 formed in the depending lug 24 formed on theunder side of the shearingarm in rear of the pivot shaft thereof;whereby the spring case will adapt itself freely to the oscillatingmovements of the shearing arm.

The strength of the springs is so adapted, and the parts are so located,proportioned and arranged, that the springs will equally balance thatportion of the weight of the shearing arm in rear of its pivot shaft,which is in excess of the weight of the shearing arm in front of itspivot shaft, and also the weight of the pitman and the cranks, so thatthe shearing arm and its connected parts will operate without imposingany weight upon the crank shaft, and will normally remain at rest in allgiven positions.

T he cylindric clutch heads 25 are secured, as by the keys 26, on theends of the crank shaft, the inner ends 27 of which heads are inabutment with the outer ends 28 of the hubs 29 of the cog gear wheels12. The annular rabbet 30 is provided in the peripheral portion of theouter end of each hub, thus forming an annular groove 31 in which theclutch finger 32 is adapted to operate.

One or mor radial recesses 33 are provided in the end of each gear wheelhub, and, as shown in Fig. 5, two of such recesses are prefe "ablyprovided in diametrically opposite relation; one side of each recessbeing provided with the squar radial abutment formed by the side of thehard steel clutch jaw 35 which is inlaid in the hub, while the otherside of each recess is formed with the shallow shoulder 36 from whicheX- tends the beveled surface 37 which inclines annularly outward to theface of the outer end 28 of the hub.

The clutch block 38 and its stem 39 are located in correspondingrecesses extending from the inner end of the clutch head and thecompression spring 4:0 is provided in corresponding recesses in the bodyof the clutch head and the end of t -e block stem, the energy of whichspring serves to press the clutch block inward toward the hub of thegear wheel, and, when not restrained, into one of the recesses thereof,whereby the forward face 3% of the clutch jaw (as the cog gear rotatesin the operation of the machine, as shown by arrows in the drawing),abuts the side 4L1. of the clutch block and thereby rotates the crankshaft with the gear wheel.

The clutch fingers 32 are radially secured on the ends of the rock shaftL2 which extends through and is journaled in the side members 1 of theframe; to which rock shaft L2 is secured the forwardly extending arm 44,on the free end of which is provided the treadle as which is located onthe operators side of the machine adjacent to the forward end thereof,so as to be readily accessible to the operator.

The lower side of the forward end of each clutch finger 32 is concavedto conformto the periphery 46 of the gear wheel hub 29, being the baseof the groove formed by the rabbet 30 in the rim of the hub, in whichgroove each finger is normally held by action of the expansion spring 48extending upward from the treadle arm to the adjacent frame member 1.

The outer side of the forward end of each clutch finger is beveled toform the inclined face 49, which is furthermore slightly inclineddownward and outward; and a correspondingly beveled notch 50 is providedat the forward outer corner in the inner side of the clutch block, sothat, when the clutch finger is in normal position in the hub groove andthe clutch block is rotating in abutment with the clutch jaw, theforward beveled end of the clutch finger, by operating in the bevelednotch 50 in the clutch block, will wedge the same outward into the headrecess and disengage the block from the jaw, and permit the gear wheelto rotate freely on the crank shaft.

The parts are preferably so proportioned and arranged that the clutchblock will be fully disengaged from the clutch jaw when the cranks areslightly in rear of their pendent position and with the pit nan insubstantially vertical position, and the jaw 51 on the forward end ofthe shearing arm is in its upper open position, as shown in the severalfigures of the drawings. With this relation of the parts, and theexcessive weight of the rear end of the shearing arm and the weight ofthe pitman and cranks being equally balanced by the springs 13, it isevident that the oscillation of the shearing arm will ordinarily stopwhen the clutch block is disengaged from the clutch jaw; because themore weight of the pendent cranks, the friction of the several journalbearings, and the inertia of the shearing arm at the end of itsoscillation, are generally sufficient to overcome the momentum of therearward swinging of the cranks and the pitman.

For the purpose of more certainly timing the stopping of the cranks whenthe clutch is disengaged, the bow spring 52 is mounted on the inner sideof one frame member in position to frictionally press against the sideof the adjacent crank in its pendent position, as shown in Fig. 4, thefrictional pressure of which spring serves to promptly and certainlystop the shearing mechanism when the crank shaft clutch is disengagedfrom the gear wheel. The friction spring is preferably secured to theframe by bolts 53 passed through the round aperture 54 in one end andthe slotted aperture 55 in the other end, thereby permitting an endwisemovement of the slotted end of the spring.

T he depression 56 is preferably provided in the face of the frictionspring 52, and the laterally beveled spud 57 is correspondingly providedon the abutting face of the crank, so that the crank will always bestopped at the same place by the entrance of the spud into thedepression. But it will be understood that neither the use of thedepression in the spring and the spud on the crank, nor the use of anyfriction spring'at all, are essential to the other features of theinvention.

In the operation of the machine as a stopmotion shear, the clutchfingers are normally held in the gear hub groove by action of thetreadle arm spring, thus holding the clutch block out of engagement withthe clutch jaws, as shown in Fig. 1, and permitting the driving shaftand gear wheels to rotate freely on the crank shaft, while the jaw ofthe shearing arm is in open position.

When the operator is ready to make a cut, the treadle is depressed bythe foot, thus throwing the clutch fingers upward above the clutch blockand permitting the same to be forced inward by the compression springsand to enter the first arriving recess and to engage the first arrivingclutch jaw in the respective gear wheel hubs; whereby the crank shaft isrotated and the shearing arm is oscillated for the cutting operation.

After starting the shearing mechanism, the operator at once releases hisfoot from the treadle, whereupon the clutch fingers are again throwndownward into the hub grooves by action of thetreadle spring, and, whenthe clutch block approaches the completion of the single rotationnecessary for a single cutting operation of the shearing arm, the clutchfingers throw the clutch blocks out of engagement with the clutch jaws,whereupon the shearing mechanism is stopped by the inertia of its partsand the pressure of the friction spring against the side of the adjacent crank.

The permanent stop pin 58 is preferably provided on the side of theframe to limit the downward movement of the treadle arm, and thetemporary stop pin 59 is preferably provided for entering into thecorrespond-' ing aperture 60 in the side of the frame for holding thetreadle arm downward against the action of its spring, and the clutchfingers upward out of the path.of the clutch blocks, when it is desiredto operate the shears with a continuous motion.

I claim:

1. A shearing machine including a base, a shearing arm fulcrumed on thebase, means for oscillating the shearing arm, and means for equallybalancing the shearing arm and pendent parts.

2. A shearing machine including a base, a shearing arm fulcrumed on thebase, means for oscillating the shearing arm, and a spring for equallybalancing the shearing arm and pendent parts.

3. A shearing machine including a base, a

arm, the pitman and the cranks.

shearing arm fulcrumed on thebase,a' crank shaft journaled on the base,a pitman .between the crank and the shearing arm, and means'for equallybalancing the shearing 4:- A shearing machine including a base, a

shaft journaled on the base, a pitman between the crank and the shearingarm, means for equally balancing the shearing arm, the pitman and thecrank, and means for intermittently rotating the crank shaft. I

6. A shearing machine including a base, a shearing arm fulcrumed on thebase and having a shearing jaw on its forward end, a crank shaftournaled on the base, a pitman between the crank and the rear end of theshearing arm, and means for equally balancing the rear end of theshearing arm, the pitman and the crank,

7. A shearing machine including a base, a shearing arm fulcrumed on thebase and having a shearing jaw on its forward end, a crank shaftjournaled on the base, a pitman between the crank and the rear end ofthe shearing arm, and a spring for equally balancing the rear end of theshearing arm, the pitman and the crank.' a

8. A shearing machineincluding a base, a shearing arm fulcrumed on thebase, a crank shaft journaled on the base, a pitman between the crankand the shearing arm, means for balancing the shearing arm, the pitmanand the crank, and a spring frictionally pressing against the side ofthe crank for stopping it in pendent position.

9. A shearing machine including a base, a shearing arm fulcrumed on thebase, a crank shaft journaled on the base, a pitman be tween the crankand the shearing arm, means for equally balancing the shearing arm, thepitman and the crank, a spring abutment on the base frictionallyimpinging the crank in pendent position, there being a depression in theface of the one and a corresponding spud on the face of the other forstopping the crank in a given position.

10. A shearing machine including a base, a shearing arm fulcrumed on thebase, a crank shaft journaled on the base, a pitman between the crankand the shearing arm, means for equally balancing the shearing arm, thepitman and the crank, a driving a shearing arm fulcrumed on the base, acrank shaft journaled on the base, a pitman between the crank and theshearing arm, means for equally balancing the shearing arm, the pitmanand the crank, a spring abutment on the base for frictionally impingingand stopping the crank in pendent position, a driving gear adapted forcontinuous operation and having a clutch connection with the crankshaft, and means for first engaging and then automatically releasing theclutch for a stop-motion operation or the l iearing arm.

12. A shearing machine including a base, a shearing arm fulcrumed on thebase, a shaft journaled on the base in operative connection with theshearing arm, a clutch head secured to and a gear wheel rotatable on theshaft, a jaw on the end'of the wheel hub, a block in the clutch head, aspring acting to force the block in the path oi. the jaw, arabbet-groove in the periphery of the hub, a clutch finger normallyresting in the groove, the end of the linger and one edge or the blockbeing correspondingly beveled, whereby the finger serves to throw theblock from the path of the jaw.

13. A shearing machine including a base, a shearing arm tulcrumed on thebase, a shaft journaled on the base in operative connection with theshearing arm, a clutch head secured to and a gear wheel rotatable on theshaft, a jaw on the end of the wheel hub, a block in the clutch head, aspring acting to force the block in the path of the jaw, a rabbet-groovein the periphery of the hub, a clutch finger normally resting in thegroove, the end of the finger and one edge of the block beinglongitudinally beveled and laterally inclined, whereby the finger servesto throw the block from the path of the jaw.

14. A shearing machine including a base, a shearing arm fulcrumed on thebase, a saatt journaled on the base in operative connection with theshearing arm, a clutch head secured-to and a gear wheel rotatable on theshaft, a jaw on the end of the wheel hub, a block in the clutch head, aspring acting to force the block in the pathjo't the jaw, arabbet-groove in the periphery ot the hub, a rock shaft journaled in thebase having a pedal arm on one side and'a clutch finger on the otherside normally resting in the groove, the end of the finger and one edgeof the block being correspondingly bevelec, whereby the finger serves tothrow the block from the path of the jaw.

15. A shearing machine including a base, a shearing arm fulcrumed on thebase, a shaft ournaled on the base in operative connection with theshearing arm, a clutch head secured to and a gear wheel rotatable on theshaft, a jaw on the end of the wheel hub, a block in the clutch head, aspring acting to force the block in the path of the jaw, a rabbet-groovein the periphery of the hub, a rock shaft journaled in the base having apedal arm on one side and a clutch finger on the other side normallyresting in the groove, the end of the finger and one edge of the blockbein correspondingly beveled, whereby the finger serves to throw theblock from the path of the jaw, with means for holding the clutch out ofthe rabbet-groove.

ALBERTUS O. SLENTZ.

Witnesses RUTH MILLER, Ptor F. Koran.

(Copies oi this patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

Washington, D. C.

